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author | manojgudi | 2013-10-07 14:26:59 +0530 |
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committer | manojgudi | 2013-10-07 14:26:59 +0530 |
commit | 6bc92d66be9975d618ac4cd104e7f5ff6e8605f2 (patch) | |
tree | 3a77657667b4ef037f712ee68a5ec86c86cba5c5 /README.hacking | |
parent | 452defdb4a78e9e826740ddf4b9673e926c568a4 (diff) | |
parent | e9576e44ef8f0ad67d8cd8a4e025a0f8da0727f8 (diff) | |
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merge from gr36_ni branch
Diffstat (limited to 'README.hacking')
-rw-r--r-- | README.hacking | 320 |
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diff --git a/README.hacking b/README.hacking new file mode 100644 index 000000000..58b269887 --- /dev/null +++ b/README.hacking @@ -0,0 +1,320 @@ +# -*- Outline -*- +# +# Copyright 2004,2007,2008,2009 Free Software Foundation, Inc. +# +# This file is part of GNU Radio +# +# GNU Radio is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3, or (at your option) +# any later version. +# +# GNU Radio is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with GNU Radio; see the file COPYING. If not, write to +# the Free Software Foundation, Inc., 51 Franklin Street, +# Boston, MA 02110-1301, USA. +# + +Random notes on coding conventions, some explanations about why things +aren't done differently, etc, etc, + + +* Boost 1.35 + +Until boost 1.35 or later is common in distributions, you'll need to +build boost from source yourself. See README.building-boost. + +Also, when running make distcheck you'll need to provide the +DISTCHECK_CONFIGURE_FLAGS. E.g., + + $ make distcheck DISTCHECK_CONFIGURE_FLAGS=--with-boost=/opt/boost_1_36_0 + + +* C++ and Python + +GNU Radio is now a hybrid system. Some parts of the system are built +in C++ and some of it in Python. In general, prefer Python to C++. +Signal processing primitives are still built in C++ for performance. + + +* C++ namespaces + +In the cleanup process, I considered putting everything in the +gnuradio namespace and dropping the Gr|gr prefix. In fact, I think +it's probably the right idea, but when I tested it out, I ran into +problems with SWIG's handling of namespaces. Bottom line, SWIG +(1.3.21) got confused and generated bad code when I started playing +around with namespaces in a not particularly convoluted way. I saw +problems using the boost::shared_ptr template in combination with +classes defined in the gnuradio namespace. It wasn't pretty... + + +* Naming conventions + +Death to CamelCaseNames! We've returned to a kinder, gentler era. +We're now using the "STL style" naming convention with a couple of +modifications since we're not using namespaces. + +With the exception of macros and other constant values, all +identifiers shall be lower case with words_separated_like_this. + +Macros and constant values (e.g., enumerated values, +static const int FOO = 23) shall be in UPPER_CASE. + + +** Global names + +All globally visible names (types, functions, variables, consts, etc) +shall begin with a "package prefix", followed by an '_'. The bulk of +the code in GNU Radio logically belongs to the "gr" package, hence +names look like gr_open_file (...). + +Large coherent bodies of code may use other package prefixes, but +let's try to keep them to a well thought out list. See the list +below. + +*** Package prefixes + +These are the current package prefixes: + + gr_ Almost everything + + gri_ Implementation primitives. Sometimes we + have both a gr_<foo> and a gri_<foo>. In that case, + gr_<foo> would be derived from gr_block and gri_<foo> + would be the low level guts of the function. + + atsc_ Code related to the Advanced Television + Standards Committee HDTV implementation + + qa_ Quality Assurance. Test code. + + +** Class data members (instance variables) + +All class data members shall begin with d_<foo>. + +The big win is when you're staring at a block of code it's obvious +which of the things being assigned to persist outside of the block. +This also keeps you from having to be creative with parameter names +for methods and constructors. You just use the same name as the +instance variable, without the d_. + +class gr_wonderfulness { + std::string d_name; + double d_wonderfulness_factor; + +public: + gr_wonderfulness (std::string name, double wonderfulness_factor) + : d_name (name), d_wonderfulness_factor (wonderfulness_factor) + { + ... + } + ... +}; + + +** Class static data members (class variables) + +All class static data members shall begin with s_<foo>. + + +** File names + +Each significant class shall be contained in it's own file. The +declaration of class gr_foo shall be in gr_foo.h, the definition in +gr_foo.cc. + + + +* Storage management + +Strongly consider using the boost smart pointer templates, scoped_ptr +and shared_ptr. scoped_ptr should be used for locals that contain +pointers to objects that we need to delete when we exit the current +scope. shared_ptr implements transparent reference counting and is a +major win. You never have to worry about calling delete. The right +thing happens. + +See http://www.boost.org/libs/smart_ptr/smart_ptr.htm + + +* Unit tests + +Build unit tests for everything non-trivial and run them after every +change. Check out Extreme Programming: +http://c2.com/cgi/wiki?ExtremeProgrammingRoadmap + +Unit tests should also be written for all examples. This should kill +off the bit rot we've been plagued with. + +** C++ unit tests + +For C++ we're using the cppunit framework. cppunit has its bad +smells, but it's mostly workable. http://cppunit.sf.net + +Currently each directory <dirname> contains files qa_<dirname>.{h,cc} +that bring together all the qa_<foo> test suites in the directory. +We ought to be able to automate this without too much trouble. + +The directory gnuradio-core/src/tests contains programs that run +the tests. test_all runs all of the registered C++ unit tests. + +As far as I can tell, the cppunit TestFactoryRegistry maybe able to be +tricked into doing what we want. As is, I don't think it's enough by +itself, since there's nothing dragging the qa* files out of the +library and into the program. I haven't tested out this idea. + +** Python unit tests + +We use the standard unittest package for unit testing of Python code. + + +* Subversion line ending styles + +All text files in the tree should have the subversion property +'svn:eol-style' set to 'native', with the following exceptions: + +config/*.m4 +configure.ac +gr-howto-write-a-block/config/*.m4 +gr-howto-write-a-block/configure.ac + +The easiest way to ensure this is to add or edit the following lines in +your svn client configuration file (~/.subversion/config): + +enable-auto-props=yes + +[auto-props] +*.c = svn:eol-style=native +*.cc = svn:eol-style=native +*.i = svn:eol-style=native +*.h = svn:eol-style=native +*.am = svn:eol-style=native +*.py = svn:eol-style=native +*.ac = svn:eol-style=LF +*.m4 = svn:eol-style=LF + +* Misc tips + +ccache, a compiler cache, can really speed up your builds. +See http://ccache.samba.org/ + +Be sure to create links for gcc and g++ + + +* Standard command line options + +When writing programs that are executable from the command line, +please follow these guidelines for command line argument names (short +and long) and types of the arguments. We list them below using the +Python optparse syntax. In general, the default value should be coded +into the help string using the "... [default=%default]" syntax. + +** Mandatory options by gr_block + +*** Audio source + +Any program using an audio source shall include: + + add_option("-I", "--audio-input", type="string", default="", + help="pcm input device name. E.g., hw:0,0 or /dev/dsp") + +The default must be "". This allows an audio module-dependent default +to be specified in the user preferences file. + + +*** Audio sink + + add_option("-O", "--audio-output", type="string", default="", + help="pcm output device name. E.g., hw:0,0 or /dev/dsp") + +The default must be "". This allows an audio module-dependent default +to be specified in the user preferences file. + + +** Standard options names by parameter + +Whenever you want an integer, use the "intx" type. This allows the +user to input decimal, hex or octal numbers. E.g., 10, 012, 0xa. + +Whenever you want a float, use the "eng_float" type. This allows the +user to input numbers with SI suffixes. E.g, 10000, 10k, 10M, 10m, 92.1M + +If your program allows the user to specify values for any of the +following parameters, please use these options to specify them: + + +To specify a frequency (typically an RF center frequency) use: + + add_option("-f", "--freq", type="eng_float", default=<your-default-here>, + help="set frequency to FREQ [default=%default]") + + +To specify a decimation factor use: + + add_option("-d", "--decim", type="intx", default=<your-default-here>, + help="set decimation rate to DECIM [default=%default]") + + +To specify an interpolation factor use: + + add_option("-i", "--interp", type="intx", default=<your-default-here>, + help="set interpolation rate to INTERP [default=%default]") + + +To specify a gain setting use: + + add_option("-g", "--gain", type="eng_float", default=<your-default-here>, + help="set gain in dB [default=%default]") + + +If your application specifies both a tx and an rx gain, use: + + add_option("", "--rx-gain", type="eng_float", default=<your-default-here>, + help="set receive gain in dB [default=%default]") + + add_option("", "--tx-gain", type="eng_float", default=<your-default-here>, + help="set transmit gain in dB [default=%default]") + + +To specify the number of channels of something use: + + add_option("-n", "--nchannels", type="intx", default=1, + help="specify number of channels [default=%default]") + + +To specify an output filename use: + + add_option("-o", "--output-filename", type="string", default=<your-default-here>, + help="specify output-filename [default=%default]") + + +To specify a rate use: + + add_option("-r", "--bit-rate", type="eng_float", default=<your-default-here>, + help="specify bit-rate [default=%default]") + or + + add_option("-r", "--sample-rate", type="eng_float", default=<your-default-here>, + help="specify sample-rate [default=%default]") + + +If your application has a verbose option, use: + + add_option('-v', '--verbose', action="store_true", default=False, + help="verbose output") + + +If your application allows the user to specify the "fast USB" options, use: + + add_option("", "--fusb-block-size", type="intx", default=0, + help="specify fast usb block size [default=%default]") + + add_option("", "--fusb-nblocks", type="intx", default=0, + help="specify number of fast usb blocks [default=%default]") |